How to obtain it. 207 
prey upon these crustaceans, that few of them practically survive. 
These figures, however, have their lesson ; they teach us of the 
enormous possibilities that exist, with regard to the increase of 
these minute creatures, where by so called artificial means they 
can be protected from their enemies, and allowed to multiply 
enormously. The food of Cyclops is produced by decaying 
vegetable matter, and minute spores. On occasion it also eats 
infusoria, or becomes a cannibal when a favourable opportunity 
occurs. It possesses but one eye, and projects itself through the 
water by means of its oar-like feet, which are ten in number. 
The third and last crustaceans of the sub-class Entomostraca 
which it is necessary to mention are the Cypride. They are 
interesting little creatures, and are abundant in some waters. 
Cypris tristriata is the commonest, although there are said 
to be fifteen recorded species in this country. They are small 
free swimming crustaceans, and are enclosed in a bivalve shell- 
like carapace. The mode of progression is 
by opening their valves slightly, and putting 
out a series of hair-like processes or cilia, 
which they move rapidly and constantly, but 
on the slightest alarm withdraw them and 
sink to the bottom. In a closely allied 
genus called Candona we find the swimming .__, Fig. 25. 
a Cypris tristriata, 
apparatus absent, and the species, some five 
in number, are not found swimming about, but crawling on the 
bottom, or on the plants growing in the water they inhabit. The 
food of the Cyp7is consists of both animal and vegetable matter, 
and they are excellent scavengers. I have seen ponds which they 
inhabit dry up in summer, but the little creatures, nothing daunted, 
bury themselves in the mud, and remain there until rain falls, and 
the pool fills up again. Should the mud be thoroughly dried by 
the sun they perish, but their eggs retain life even under such 
trying circumstances, and will hatch and produce a fresh crop in 
a few days, when placed in the water. 
As we work out the life histories and developments of some 
of these interesting little creatures, we are forcibly reminded of 
the language of the Psalmist, ‘“‘O Lord, how manifold are Thy 
works! in wisdom hast Thou made them: all the earth is full of 
enlarged. 
